NXP Semiconductors MC68HC11A1MFNER

Overview

MC68HC11A1MFNER from NXP Semiconductors (formerly Freescale) is an HCMOS 8-bit single-chip microcontroller featuring 512 bytes of on-chip EEPROM, 256 bytes of RAM, and a 20 MHz maximum CPU clock. It integrates an 8-channel 8-bit ADC, dual serial interfaces (SCI and SPI), programmable timer system with input capture/output compare, and supports single-chip, expanded multiplexed, and bootstrap operating modes. It is used in industrial control modules requiring deterministic real-time I/O handling and nonvolatile parameter storage.

For engineers reviewing the MC68HC11A1MFNER datasheet, MC68HC11A1MFNER pinout, MC68HC11A1MFNER application, or MC68HC11A1MFNER equivalent, key selection considerations include its 512-byte EEPROM endurance (10k write/erase cycles), 8-bit ADC conversion time (25 µs typical), SCI baud rate support up to 19.2 kbps at 2 MHz bus clock, and compatibility with M68HC11 family development tools including EVB and EVBU boards.

Technical Context

The MC68HC11A1MFNER implements a Harvard-architecture CPU core with 16-bit address bus and 8-bit data bus, executing instructions from on-chip ROM or external memory depending on operating mode. Its memory map includes fixed register locations for peripheral control (e.g., ADCTL at $1024, SCCR2 at $102D), and configurable INIT register enabling RAM/ROM/I/O mapping.

It supports three primary operating modes: single-chip (all peripherals active, no external bus), expanded multiplexed (external memory interface via AD0–AD7, A8–A15, E, R/W), and bootstrap (on-chip monitor ROM enables in-circuit programming via SCI). Reset sources include external RESET pin, power-on reset, COP timeout, and clock monitor failure - each triggering defined vector addresses and register initialization sequences.

Key Specifications

Pinout & Package

MC68HC11A1MFNER is housed in a 48-pin plastic dual in-line package (DIP) with 0.6-inch body width and 0.1-inch pin pitch. Pin assignments follow standard M68HC11Ax pinout layout, with dedicated VDD/VSS pairs, XTAL/EXTAL oscillator inputs, E clock output, IRQ/XIRQ interrupt inputs, MODA/MODB mode select pins, and five bidirectional I/O ports (A–E).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit microcontroller applications.

Compared with MC68HC11A1MFNER, MC68HC11E9CP offers enhanced analog precision in a different package, while MC9S12XDP512 delivers architectural scalability at the cost of compatibility - making the former a functional upgrade and the latter a platform evolution.

Availability

MC68HC11A1MFNER is available at Aetrix Electronics and suitable for industrial motor control, automotive body electronics, medical infusion pumps, and building automation sensor nodes requiring stable component supply and long-term lifecycle support.

Supply support for MC68HC11A1MFNER includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

NXP Semiconductors (formerly Freescale Semiconductor) is a global semiconductor leader specializing in secure connectivity solutions for automotive, industrial, and IoT applications.

The MC68HC11A1MFNER belongs to the legacy M68HC11 microcontroller family, designed for deterministic real-time control in resource-constrained embedded systems where reliability, low power, and on-chip nonvolatile memory are essential.

FAQ

What is the maximum operating frequency of the MC68HC11A1MFNER?

The MC68HC11A1MFNER supports a maximum bus clock frequency of 2 MHz, derived from a 4 MHz crystal (or external clock) applied to XTAL/EXTAL. Its internal CPU core operates at this bus clock rate, enabling instruction execution at up to 2 million cycles per second. The device is fully static, allowing it to operate down to DC clock speeds for ultra-low-power applications.

Does the MC68HC11A1MFNER include a hardware watchdog timer?

Yes, the MC68HC11A1MFNER includes a Computer Operating Properly (COP) watchdog timer with programmable timeout periods (ranging from 2.5 ms to 1.6 s) controlled by CR1/CR0 bits in the OPTION register. If the COP is enabled and not cleared within the selected timeout window, it triggers a hardware reset - a critical feature for safety-critical applications like medical devices or industrial controllers.

How much EEPROM does the MC68HC11A1MFNER have, and what is its endurance?

The MC68HC11A1MFNER contains 512 bytes of on-chip EEPROM, organized as 64 rows × 8 bytes. It is rated for a minimum of 10,000 write/erase cycles per location under industrial temperature conditions (−40°C to +85°C), with data retention exceeding 10 years. This allows reliable storage of calibration coefficients, device IDs, or user configurations without external memory.

Can the MC68HC11A1MFNER operate in low-power modes, and how are they entered?

Yes, the MC68HC11A1MFNER supports two low-power modes: WAIT and STOP. WAIT mode halts the CPU while keeping peripherals and clocks active - entered via the WAIT instruction. STOP mode gates all internal clocks except the real-time interrupt (RTI) source - entered via the STOP instruction. Both modes reduce current consumption significantly, with STOP mode drawing less than 15 µA typical at 5 V, ideal for battery-powered sensor nodes.

Is the MC68HC11A1MFNER pin-compatible with other M68HC11 variants like the MC68HC11A8?

No, the MC68HC11A1MFNER is not pin-compatible with the MC68HC11A8. While both belong to the M68HC11 family and share identical core architecture and peripheral register maps, the MC68HC11A1MFNER uses a 48-pin DIP package, whereas the MC68HC11A8 is available in 52-pin PLCC, 48-pin DIP, and 64-pin QFP packages - with differing pin counts and layouts across variants. Always verify package-specific pin assignments before substitution.